Catalyst containing metal cluster in structurally collapsed zeolite, and use thereof

ABSTRACT

This invention relates to a hydrogen spillover-based catalyst and use thereof, wherein a hydrogen activation metal cluster is dispersed in the form of being encapsulated in a crystalline or amorphous aluminosilicate matrix which is partially or fully structurally collapsed zeolite, thereby exhibiting high hydroprocessing or dehydrogenation activity and suppressed C—C hydrogenolysis activity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Phase of PCT/KR2014/003491, filed Apr.22, 2014, which claims priority from Korean Application No.10-2013-0044357, filed Apr. 22, 2013 and Korean Application No.10-2014-0045750, filed Apr. 17, 2014, the disclosures of which are allincorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a hydrogen spillover-based catalysthaving a metal cluster encapsulated in structurally collapsed zeolite,and to use thereof. More particularly, the present invention relates toa hydrogen spillover-based catalyst wherein a hydrogen activation metalcluster is dispersed in a crystalline or amorphous aluminosilicatematrix which is partially or fully structurally collapsed zeolite tothus attain high hydroprocessing or dehydrogenation activity andsuppressed C—C hydrogenolysis activity, and to use thereof.

BACKGROUND ART

Recently, thorough research into use of heavy oil having high aromaticcontent while containing large amounts of heteroatoms such as sulfur andnitrogen is ongoing, and also the demand for a middle distillate whichis the feed for transport fuel is increasing. Especially,hydroprocessing in a refining process, including hydrogenation,hydrodesulfurization (HDS), hydrodenitrogenation (HDN), etc. is regardedas important.

As the catalyst useful for such hydroprocessing, there is required todevelop a catalyst which exhibits high hydroprocessing activity even inthe presence of an impurity such as sulfur (acting as a catalystpoison), and also suppresses C—C bond cleavage (hydrogenolysis) tothereby inhibit production of hydrocarbons having comparatively lowvalue due to a decrease in the number of carbons. The catalyst forhydroprocessing may include molybdenum sulfide such as NiMo, CoMo, etc.and a precious metal such as platinum (Pt), palladium (Pd), etc., whichare currently widely used. In this regard, a molybdenum sulfide-basedcatalyst is known to have lower activity but to be more resistant tosulfur, compared to a precious metal-based catalyst. On the other hand,the precious metal-based catalyst shows high activity in the absence ofsulfur but suffers from being rapidly deactivated in the presence ofsulfur.

Meanwhile, in order to suppress hydrogenolysis during hydroprocessing,formation of an alloy such as Pt—Sn, Pt—In, etc. (F. B. Passos et al.,J. Catal., 160:106, 1996), or partial poisoning of the surface of metalwith a catalyst poison such as sulfur (P. Govind Menon, Eng. Chem. Res.,36:3282, 1997) has been studied. However, such methods are problematicbecause molecular sulfur has to be continuously added to the feed andbyproducts may be generated by the added sulfur.

An alternative to the method of overcoming limitations of theconventional precious metal-based hydroprocessing catalyst, for example,supporting of metal particles in microporous (pore diameter of less than1 nm) zeolite to thus enhance stability is under study. Specifically, C.Song et al. have researched hydrogenation of naphthalene in the presenceof a sulfur compound after supporting of Pt in mordernite type zeolite(C. Song et al., Energy & Fuels, 11:656, 1997). It was reported thatmordernite has two cages with different sizes, wherein hydrogenation iscarried out only on Pt supported in the cage having a large size towhich an organic molecule is accessible, and only hydrogen may beselectively diffused and activated on Pt supported in the cage having asmall size, so that the activated hydrogen atom may move to Pt supportedin the cage having a large size through a spillover phenomenon tothereby suppress deactivation of metal. However, as hydrogen sulfide(H₂S) produced upon decomposition of a sulfur compound diffuses into thecage having a small size, the metal in the cage having a small size mayalso become deactivated, and thus the effects thereof are limited.

In a study conducted by Hong Yang et al., A-type zeolite having Ptsupported therein was used as a catalyst for hydrogenation ofnaphthalene (Hong Yang et al., J. Catal., 243:36, 2006; US PatentPublication NO. 2009/0048094). Specifically, the catalyst was designedsuch that, as a result of decreasing the final pore size of a zeolitecage up to about 2.9˜3.5 Å by incorporating precious metal nanoparticlesin the zeolite cage and then performing post-treatment (CVD, CLD, cationexchange or combination thereof), only molecular hydrogen may passthrough the pores but an organic sulfur molecule (H₂S having a kinematicdiameter of 3.6 Å) cannot pass through the pores to thereby suppresscontacting of the precious metal component with the poisoning material,that is, the sulfur compound. By means of such a catalytic structure,activated hydrogen (i.e. dissociated hydrogen) by precious metalundergoes spillover through the zeolite pores to thus inducehydrogenation, and may recycle the catalyst therearound (the sulfurcompound which poisoned catalyst sites is removed by hydrogen).Furthermore, such researchers have made attempts to decrease the poresize by supporting Pt in A-type zeolite and then performing ion-exchangewith K⁺ and coating with silica. It was reported that the catalyst thussynthesized enables naphthalene, which cannot diffuse into zeolitepores, to be successfully hydrogenated through spillover of activatedhydrogen, and is very resistant to sulfur.

In a study conducted by Chen et al., hydroprocessing reactivity foractual crude oil reactants containing diverse sulfur compounds wasmeasured using P-type zeolite having Pt supported therein, in whichP-type zeolite has a smaller pore size than A-type zeolite (Song Chen etal., Proceedings of the World Congress on Engineering and ComputerScience, vol. 2, 2010). This paper proposed the catalyst to beconfigured such that Pt is encapsulated in the sodalite cage of P-typezeolite on the basis of shape selectivity and hydrogen spilloverprinciple. In this case, H₂ passes through the pores, whereas H₂S doesnot. Hence, even when such a catalyst is exposed to a highsulfur-containing environment, hydroprocessing activity thereof may bemaintained.

Despite the above research results, there are still needs for hydrogenspillover-based catalysts which exhibit further improved catalyticactivity in the art.

DISCLOSURE Technical Problem

Therefore, an embodiment of the present invention is intended to providea hydrogen spillover-based catalyst and a preparation method thereof,wherein a zeolite crystal structure containing a metal cluster ispartially or fully collapsed, and thereby the activity distinct from aconventional catalyst may be attained.

Also, another embodiment of the present invention is intended to providea hydrogen spillover-based catalyst and a preparation method thereof,wherein the catalyst may exhibit high hydroprocessing activity, maysuppress C—C bond cleavage, and may ensure superior thermal stability.

Technical Solution

According to a first aspect of the present invention, a hydrogenspillover-based catalyst includes crystalline or amorphousaluminosilicate formed by partial or full structural collapse of zeolitehaving a silica/alumina molar ratio of 2 or less; and a hydrogenactivation metal (M) cluster encapsulated in the aluminosilicate,wherein changes in hydrogen and carbon monoxide chemisorption amountsdepending on the temperature satisfy the following relation:0.7*(H/M ₃₇₃ +H/M ₄₇₃ +H/M ₅₇₃)/3>(CO/M ₃₇₃ +CO/M ₄₇₃ +CO/M ₅₇₃)/3

wherein H/M is the chemisorption amount (mol) of a hydrogen atom pertotal mol of M, CO/M is the chemisorption amount (mol) of carbonmonoxide per total mol of M, and subscripts represent adsorptiontemperatures (K).

In an exemplary embodiment, the catalyst shows the following:0.8(MainP _(zeolite))>(MainP _(collapse))

wherein MainP_(zeolite) is the base area of the highest peak among XRDpeaks of zeolite before collapse, and MainP_(collapse) is the base areaof an XRD peak at the same 2θ of zeolite after collapse.

In an exemplary embodiment, the alumina/silica molar ratio of zeolitemay be 1˜2.

In an exemplary embodiment, the hydrogen activation metal may be any oneor more selected from among Groups IB, VIIB and VIII metals on theperiodic table, and specific examples thereof may include Co, Ni, Cu,Ru, Rh, Pd, Ag, Ir, Pt and/or Au.

In addition, a second aspect of the present invention provides a methodof preparing a hydrogen spillover-based catalyst, including (a)providing zeolite containing a hydrogen activation metal (M) clustertherein and having a silica/alumina molar ratio of 2 or less; (b)ion-exchanging the zeolite with an ammonium ion (NH₄ ⁺); and (c)thermally treating the ion-exchanged zeolite to thus partially or fullycollapse a zeolite framework so that the hydrogen activation metalcluster is encapsulated in crystalline or amorphous aluminosilicate,wherein changes in hydrogen and carbon monoxide chemisorption amountsdepending on the temperature satisfies the following relation:0.7*(H/M ₃₇₃ +H/M ₄₇₃ +H/M ₅₇₃)/3>(CO/M ₃₇₃ +CO/M ₄₇₃ +CO/M ₅₇₃)/3

wherein H/M is the chemisorption amount (mol) of a hydrogen atom pertotal mol of M, CO/M is the chemisorption amount (mol) of carbonmonoxide per total mol of M, and subscripts represent adsorptiontemperatures (K).

In an exemplary embodiment, the zeolite may be P-type zeolite, A-typezeolite or X-type zeolite. Particularly useful is A-type zeolite.

In addition, a third aspect of the present invention provides ahydroprocessing/dehydrogenation method, including providing ahydrocarbon feed; and contacting the hydrocarbon feed with a hydrogenspillover-based catalyst in the presence of hydrogen.

As such, the hydrogen spillover-based catalyst includes crystalline oramorphous aluminosilicate formed by partial or full structural collapseof zeolite having a silica/alumina molar ratio of 2 or less; and ahydrogen activation metal (M) cluster encapsulated in thealuminosilicate, wherein changes in hydrogen and carbon monoxidechemisorption amounts depending on the temperature satisfy the followingrelation:0.7*(H/M ₃₇₃ +H/M ₄₇₃ +H/M ₅₇₃)/3>(CO/M ₃₇₃ +CO/M ₄₇₃ +CO/M ₅₇₃)/3

wherein H/M is the chemisorption amount (mol) of a hydrogen atom pertotal mol of M, CO/M is the chemisorption amount (mol) of carbonmonoxide per total mol of M, and subscripts represent adsorptiontemperatures (K).

Advantageous Effects

According to embodiments of the present invention, a hydrogenspillover-based catalyst is configured such that a hydrogen activationmetal cluster is encapsulated in crystalline or amorphousaluminosilicate formed by partial or full structural collapse ofzeolite, and thus molecular hydrogen cannot diffuse into the catalyst atlow temperature. Ultimately, active sites of hydrogen are separated fromreactive sites with an organic material, thereby preventing a catalystpoison from being adsorbed to the surface of metal and exhibitingreaction properties different from conventional metal-supportedcatalysts reacting on the surface of metal, that is, high catalyticactivity (hydrogenation, hydrodeoxygenation, hydrodenitrogenation,hydrodesulfurization, hydroisomerization, dehydrogenation, etc.) and lowC—C hydrogenolysis activity (by about 70% or less compared to thehydrogenolysis activity of a conventional Pt/SiO₂ catalyst obtained bywet impregnation). Also, the hydrogen activation metal is encapsulatedin structurally stable aluminosilicate, thereby preventing sintering ofthe metal, consequently ensuring superior thermal stability.

DESCRIPTION OF DRAWING

FIG. 1 schematically illustrates a hydrogen spillover mechanismoccurring in a catalyst configured such that a hydrogen activation metalcluster is encapsulated (supported) in crystalline or amorphousaluminosilicate formed by structural collapse of zeolite, according toan embodiment of the present invention;

FIG. 2 illustrates the results of measurement of physical/chemicalproperties of samples (Pt/NaA-0, Pt/NaA-0.24 and Pt/NaA-0.95) in whichPt is selectively encapsulated (supported) in NaA zeolites havingvarious BET areas, samples (Pt/NaHA-0, Pt/NaHA-0.24 and Pt/NaHA-0.95) inwhich a Pt cluster is encapsulated (supported) in aluminosilicate formedby partial structural collapse of NaA zeolite, samples (Pt/HA-0,Pt/HA-0.24 and Pt/HA-0.95) in which a Pt cluster is encapsulated(supported) in aluminosilicate formed by full structural collapse of NaAzeolite, and a common Pt/SiO₂ sample prepared by an conventional wetimpregnation process, in Example 1;

FIG. 3 is of graphs illustrating the results of XRD analysis of samples(Pt/NaA-0, Pt/NaA-0.24 and Pt/NaA-0.95) in which Pt is selectivelyencapsulated (supported) in NaA zeolites having various BET areas,samples (Pt/NaHA-0, Pt/NaHA-0.24 and Pt/NaHA-0.95) in which a Pt clusteris encapsulated (supported) in aluminosilicate formed by partialstructural collapse of NaA zeolite, and samples (Pt/HA-0, Pt/HA-0.24 andPt/HA-0.95) in which a Pt cluster is encapsulated (supported) inaluminosilicate formed by full structural collapse of NaA zeolite, inExample 1;

FIG. 4 is of graphs illustrating the H₂ and CO chemisorption resultsdepending on the temperature in samples (Pt/NaA-0, Pt/NaA-0.24 andPt/NaA-0.95) in which Pt is selectively encapsulated (supported) in NaAzeolites having various BET areas, samples (Pt/NaHA-0, Pt/NaHA-0.24 andPt/NaHA-0.95) in which a Pt cluster is encapsulated (supported) inaluminosilicate formed by partial structural collapse of NaA zeolite,and samples (Pt/HA-0, Pt/HA-0.24 and Pt/HA-0.95) in which a Pt clusteris encapsulated (supported) in aluminosilicate formed by full structuralcollapse of NaA zeolite, in Example 1;

FIG. 5 illustrates TEM images of samples (Pt/NaA-0, Pt/NaA-0.24 andPt/NaA-0.95) in which Pt is selectively encapsulated (supported) in NaAzeolites having various BET areas, and samples (Pt/HA-0, Pt/HA-0.24 andPt/HA-0.95) in which a Pt cluster is encapsulated (supported) inaluminosilicate formed by full structural collapse of NaA zeolite, inExample 1;

FIG. 6 is of graphs illustrating the results of nuclear magneticresonance of a sample (Pt/NaA-0) in which Pt is selectively encapsulated(supported) in NaA zeolite, a sample (Pt/NaHA-0) in which a Pt clusteris encapsulated (supported) in aluminosilicate formed by partialstructural collapse of NaA zeolite, and a sample (Pt/HA-0) in which a Ptcluster is encapsulated (supported) in aluminosilicate formed by fullstructural collapse of NaA zeolite, in Example 2;

FIG. 7 is a graph illustrating the results ({circle around (1)}; Pt—Ptcoordination, {circle around (2)}; Pt—S coordination) of XAFS (X-rayabsorption fine structure) analysis after respective H₂S pretreatment ofa sample (Pt/HA-0) in which a Pt cluster is encapsulated (supported) inaluminosilicate formed by full structural collapse of NaA zeolite, and acommon Pt/SiO₂ sample, in Example 3;

FIG. 8 is a graph illustrating benzene hydrogenation turnover rate (TOR)per total mol of Pt in samples (Pt/NaA-0, Pt/NaA-0.24 and Pt/NaA-0.95)in which Pt is selectively encapsulated (supported) in NaA zeoliteshaving various BET areas, samples (Pt/NaHA-0, Pt/NaHA-0.24 andPt/NaHA-0.95) in which a Pt cluster is encapsulated (supported) inaluminosilicate formed by partial structural collapse of NaA zeolite,samples (Pt/HA-0, Pt/HA-0.24 and Pt/HA-0.95) in which a Pt cluster isencapsulated (supported) in aluminosilicate formed by full structuralcollapse of NaA zeolite, and a common Pt/SiO₂ sample, in Example 4;

FIG. 9 is a graph illustrating cyclohexane dehydrogenation TOR per totalmol of Pt in samples (Pt/NaA-0, Pt/NaA-0.24 and Pt/NaA-0.95) in which Ptis selectively encapsulated (supported) in NaA zeolites having variousBET areas, samples (Pt/NaHA-0, Pt/NaHA-0.24 and Pt/NaHA-0.95) in which aPt cluster is encapsulated (supported) in aluminosilicate formed bypartial structural collapse of NaA zeolite, samples (Pt/HA-0, Pt/HA-0.24and Pt/HA-0.95) in which a Pt cluster is encapsulated (supported) inaluminosilicate formed by full structural collapse of NaA zeolite, and acommon Pt/SiO₂ sample, in Example 5;

FIG. 10 is a graph illustrating thiophene hydrodesulfurization TOR pertotal mol of Pt in samples (Pt/HA-0, Pt/HA-0.24 and Pt/HA-0.95) in whicha Pt cluster is encapsulated (supported) in aluminosilicate formed byfull structural collapse of NaA zeolite, and a common Pt/SiO₂ sample, inExample 6;

FIG. 11 is a graph illustrating propane hydrogenolysis TOR per total molof Pt in samples (Pt/NaA-0, Pt/NaA-0.24 and Pt/NaA-0.95) in which Pt isselectively encapsulated (supported) in NaA zeolites having various BETareas, samples (Pt/NaHA-0, Pt/NaHA-0.24 and Pt/NaHA-0.95) in which a Ptcluster is encapsulated (supported) in aluminosilicate formed by partialstructural collapse of NaA zeolite, samples (Pt/HA-0, Pt/HA-0.24 andPt/HA-0.95) in which a Pt cluster is encapsulated (supported) inaluminosilicate formed by full structural collapse of NaA zeolite, and acommon Pt/SiO₂ sample, in Example 7;

FIG. 12 is of graphs illustrating propane dehydrogenation TOR andpropylene selectivity of a sample (Pt/NaHA-0.95) in which Pt isencapsulated (supported) in partially structurally collapsed amorphousaluminosilicate, and a common Pt/SiO₂ sample, in Example 8;

FIG. 13 illustrates TEM images before/after thermal treatment (973 K, 12hr) of a Pt cluster in a sample (Pt/NaHA-0.95) in which Pt isencapsulated (supported) in fully structurally collapsed amorphousaluminosilicate, in Example 9;

FIG. 14 is a graph illustrating the results of XRD analysis of a sample(Pt/NaX) in which a Pt cluster is encapsulated (supported) in common NaXzeolite and a sample (Pt/HX) in which a Pt cluster is encapsulated(supported) in aluminosilicate formed by full structural collapse of NaXzeolite, in Example 10;

FIG. 15 is of graphs illustrating the results of H₂ and CO chemisorptiondepending on the temperature in a sample (Pt/NaX) in which a Pt clusteris encapsulated (supported) in common NaX zeolite and a sample (Pt/HX)in which a Pt cluster is encapsulated (supported) in aluminosilicateformed by full structural collapse of NaX zeolite, in Example 10;

FIG. 16 is of graphs illustrating the results of nuclear magneticresonance of a sample (Pt/NaX) in which a Pt cluster is encapsulated(supported) in common NaX zeolite and a sample (Pt/HX) in which a Ptcluster is encapsulated (supported) in aluminosilicate formed by fullstructural collapse of NaX zeolite, in Example 10;

FIG. 17 is a graph illustrating benzene hydrogenation TOR per total molof Pt in a sample (Pt/NaX) in which a Pt cluster is encapsulated(supported) in common NaX zeolite and a sample (Pt/HX) in which a Ptcluster is encapsulated (supported) in aluminosilicate formed by fullstructural collapse of NaX zeolite, in Example 11;

FIG. 18 is a graph illustrating propane hydrogenolysis TOR per total molof Pt in a sample (Pt/NaX) in which a Pt cluster is encapsulated(supported) in common NaX zeolite and a sample (Pt/HX) in which a Ptcluster is encapsulated (supported) in aluminosilicate formed by fullstructural collapse of NaX zeolite, in Example 12; and

FIG. 19 is of graphs illustrating propane dehydrogenation TOR andpropylene selectivity of a sample (Pt/NaX) in which a Pt cluster isencapsulated (supported) in common NaX zeolite and a sample (Pt/HX) inwhich a Pt cluster is encapsulated (supported) in aluminosilicate formedby full structural collapse of NaX zeolite, in Example 13.

BEST MODE

The present invention may be accomplished by the following description.The following description is to be understood to disclose embodiments ofthe present invention, and the present invention is not necessarilylimited thereto. Also, the appended drawings are used to aidunderstanding of the present invention, and the present invention is notlimited thereto, and details on individual components may be properlyunderstood by the specific purpose of the relevant description below.

The terms used herein may be defined as follows.

The term “hydrogen activation metal” broadly refers to a metal able toform activated hydrogen, that is, dissociated hydrogen, by contact withmolecular hydrogen.

The term “hydrogen spillover” refers to diffusion of dissociatedhydrogen (i.e. activated hydrogen atoms) from a hydrogen-rich metalcluster, where hydrogen atoms are produced through dissociation ofmolecular hydrogen, to the surface of a support where hydrogendissociation is improbable.

The term “hydroprocessing” refers to any catalytic process usinghydrogen, and typically includes reaction of a hydrocarbon distillatewith hydrogen in the presence of a catalyst. Examples thereof mayinclude hydrogenation, hydrodesulfurization, hydrodenitrogenation,hydrodewaxing (hydroisomerization), hydrodeoxygenation, etc.

The term “hydrogenation” refers to a reaction for increasing hydrogencontent in a hydrocarbon compound by chemically adding hydrogen to atleast a portion of the hydrocarbon compound through contact of thehydrocarbon compound with a catalyst in the presence of hydrogen, andtypically includes saturation reactions such as olefin hydrogenation andaromatic hydrogenation.

The term “hydrodewaxing” broadly refers to a reaction for removing a waxcomponent (especially n-paraffin) from a hydrocarbon distillate in thepresence of hydrogen, and narrowly refers to a reaction for typicallyconverting n-paraffin into iso-paraffin as “hydroisomerization.”

The term “hydrodesulfurization” refers to a process for removing asulfur component from a hydrocarbon distillate in the presence ofhydrogen supply.

The term “hydrodenitrogenation” refers to a process for removing anitrogen component from a hydrocarbon distillate in the presence ofhydrogen supply.

The term “hydrodeoxygenation” refers to a reaction for removing oxygenin the form of water from a compound in the presence of hydrogen supply.

The term “dehydrogenation” refers to a reaction for removing hydrogenfrom a compound.

The term “C—C hydrogenolysis” refers to cleavage of a single bondbetween carbon and carbon by hydrogen.

According to an embodiment of the present invention, a hydrogenspillover-based catalyst is configured such that a hydrogen activationmetal (M) cluster is encapsulated in aluminosilicate to which partial orfull (or entire) zeolite structure is collapsed.

In the present invention, the chemisorption amount of each of hydrogen(H₂) and carbon monoxide (CO) may be measured by a volumetric methodknown in the art. This is because an increase in hydrogen chemisorptionamount depending on the temperature in a structurally collapsed materialsuch as the catalyst according to the present embodiment may beaccurately measured by a volumetric method. In the case where thehydrogen chemisorption amount is measured by a pulse method as a methodother than the volumetric method, limitations are imposed on actuallyobserving the increase in the hydrogen chemisorption amount depending onthe temperature. This is considered to be due to insufficientequilibrium time in the pulse method. Specifically, because the rate ofdiffusion of hydrogen into the catalyst even at high temperature is notsufficiently high, the measurement method for allowing hydrogen to flowin the form of pulse in the catalyst, such as the pulse method, makes itdifficult to ascertain the increase in chemisorption amount.

In the present embodiment, upon measurement of hydrogen (H₂) and carbonmonoxide (CO) chemisorption amounts, as the adsorption temperaturerises, H₂ shows a tendency to increase the adsorption amount.Specifically, hydrogen and carbon monoxide chemisorption propertiesdepending on the temperature are as follows:0.7*(H/M ₃₇₃ +H/M ₄₇₃ +H/M ₅₇₃)/3>(CO/M ₃₇₃ +CO/M ₄₇₃ +CO/M ₅₇₃)/3

wherein H/M is the chemisorption amount (mol) of a hydrogen atom pertotal mol of M, CO/M is the chemisorption amount (mol) of carbonmonoxide per total mol of M, and subscripts represent the adsorptiontemperatures (K).

In a typical hydrogenation catalyst having externally exposed metal anda catalyst configured such that a metal is encapsulated in zeolite thestructure of which is not collapsed (where hydrogen is accessible to thesurface of metal at room temperature), kinetic energy of an adsorptionmolecule is increased in proportion to a rise in the adsorptiontemperature, thus lowering the chemisorption amount. The reason why thecatalyst according to the present embodiment shows hydrogen adsorptionproperties different from typically expected catalytic behavior is thatmolecular hydrogen is difficult to diffuse into structurally collapsedaluminosilicate at low temperature (less than 323 K) but may diffuseinto the catalyst depending on the temperature rise. In the case ofcarbon monoxide, even when the temperature rises, the adsorption amountis not increased, and thus hydrogen and carbon monoxide chemisorptionproperties as above are exhibited.

FIG. 1 schematically illustrates a hydrogen spillover mechanism in acatalyst configured such that a hydrogen activation metal cluster isencapsulated (supported) in aluminosilicate formed by structuralcollapse of zeolite.

As illustrated in this drawing, the hydrogen activation metal (e.g. Pt)is encapsulated in aluminosilicate formed by structural collapse ofzeolite (e.g. A-type zeolite or X-type zeolite). As such, becausealuminosilicate has micropores (e.g. fully collapsed aluminosilicate hasa diameter of less than about 0.29 nm at room temperature), a verysimple catalyst poison component such as hydrogen sulfide (H₂S) as wellas an organic sulfur compound (e.g. thiophene) cannot diffuse(inaccessible) to the surface of metal. In particular, it is difficultfor molecular hydrogen to diffuse to the surface of metal inaluminosilicate at low temperature.

However, as molecular hydrogen selectively diffuses to the surface ofmetal in the catalyst depending on the temperature rise (the hydrogenchemisorption amount increases), the molecular hydrogen is dissociatedby the metal, thereby producing activated hydrogen. The activatedhydrogen is moved to the surface of the catalyst through the microporesof aluminosilicate and thus reacts with an organic molecule (in thedrawing, an organic sulfur compound, etc.) which is present on thesurface, producing hydrocarbon and hydrogen sulfide.

Unlike the spillover principle in the hydrogenation as illustrated inFIG. 1, hydrogen is removed from the organic molecule upondehydrogenation. In this case, a reverse spillover phenomenon occurs(specifically, hydrogen atoms produced by dehydrogenation of cycloalkanesuch as cyclohexane diffuse to the surface of metal through microporesof aluminosilicate, and are recombined to produce molecular hydrogen).

The catalyst according to the embodiment of the present inventionexhibits superior hydroprocessing and dehydrogenation activities,compared to a metal-containing catalyst having a large crystal size andan unchanged zeolite structure. Although the present invention is notconfined to a specific theory, such activity improvements may beelucidated by rapid diffusion of molecular hydrogen to the surface ofmetal in the catalyst because of decrease in thickness of the frameworkand in a length of a diffusion pathway in the aluminosilicate matrix,more rapid movement of activated hydrogen to the surface ofaluminosilicate, or an increase in the number of active sites on thesurface of the aluminosilicate matrix where spillover hydrogen is added(hydrogenation) or is removed (dehydrogenation) from the reactantmolecule.

According to an embodiment, zeolite may be partially or fullystructurally collapsed by subjecting zolite having high Al content tosubsequent ion exchange and thermal treatment. The silica/alumina molarratio (SAR) of zeolite before collapse may be about 2 or less and moreparticularly may be in the range of about 1˜2. When using zeolite havinga comparatively low SAR (zeolite having high Al content), the crystalstructure thereof may be collapsed by subsequent ion exchange andthermal treatment. In this regard, SAR of zeolite before collapsebecomes substantially equal to that of crystalline or amorphousaluminosilicate after collapse (partial or full collapse).

In an embodiment, the metal encapsulated in structurally collapsedzeolite is a hydrogen activation metal and is not limited to specificspecies, but may include any one or more selected from among Groups IB,VIIB and VIII on the periodic table. More specifically, a typicalhydrogen activation metal may be Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Ptand/or Au. The hydrogen activation metal is encapsulated in thealuminosilicate matrix and thus dispersed in the form of a cluster, andthe diameter of the metal cluster may be for example about 0.5˜50 nm,particularly about 0.5˜10 nm, and more particularly about 0.5˜2 nm.Also, the amount of the hydrogen activation metal in the catalyst may befor example about 0.01˜10 wt %, particularly about 0.1˜2 wt %, and moreparticularly about 0.5˜1.5 wt %, based on the weight of the catalyst.

Also, the BET specific surface area of the catalyst shows a tendency todecrease in proportion to an increase in the degree of collapse ofzeolite. As such, the typical specific surface area of partially orfully structurally collapsed zeolite (i.e. crystalline or amorphousaluminosilicate) may be for example about 1˜800 m²/g, particularly about2˜200 m²/g, and more particularly about 2˜60 m²/g.

In an exemplary embodiment, the alkali metal/Al molar ratio in thecatalyst may be for example about 0.9 or less, particularly about0.01˜0.8, and more particularly about 0.05˜0.6 (alkali metal used uponpreparation of zeolite, or the case where alkali metal ion-containingzeolite is ion-exchanged with another alkali metal and then with anammonium ion to thereby collapse the structure thereof, as will bedescribed later). In an alternative embodiment, the alkaline earthmetal/Al molar ratio in the catalyst may be for example about 0.45 orless, particularly about 0.005˜0.4, and more particularly about0.025˜0.3 (the case where alkali metal ion-containing zeolite ision-exchanged with an alkaline earth metal and then with an ammonium ionto thereby collapse the structure thereof, as will be described later).

When partially or fully structurally collapsing the zeolite, XRD (X-rayDiffraction) peaks decrease, and specifically the following propertiesare shown:0.8(MainP _(zeolite))>(MainP _(collapse))

wherein MainP_(zeolite) is the base area of the highest peak among XRDpeaks of zeolite before collapse, and MainP_(collapse) is the base areaof the XRD peak at the same 2θ of zeolite after collapse.

Meanwhile, the catalyst has a low hydrogen chemisorption amount to theextent that molecular hydrogen is inaccessible to the metal encapsulatedin aluminosilicate at low temperature. The exemplary chemisorptionranges (at different temperatures) are given in Tables 1 and 2 below.

TABLE 1 Hydrogen chemisorption ranges at different temperatures uponpartial and full structural collapse Temp. (K) Comprehensive range (H/M)Specific range (H/M) 323   0~0.3    0~0.15 373 0.005~0.5  0.01~0.3 4730.02~0.5 0.03~0.3 573 0.05~0.5 0.08~0.3

TABLE 2 Hydrogen chemisorption ranges at different temperatures uponfull structural collapse Temp. (K) Comprehensive range (H/M) Specificrange (H/M) 323   0~0.1   0~0.05 373   0~0.2   0~0.15 473 0.01~0.20.05~0.15 573 0.02~0.2 0.08~0.15

In an exemplary embodiment, the catalyst configured such that a hydrogenactivation metal is encapsulated in aluminosilicate which isstructurally collapsed zeolite may be additionally ion-exchanged with avariety of cations, and examples of such cations may include metal ionsof Groups IA, IIA, IIIB, VII, IB, VIII, etc. on the periodic table.

In an exemplary embodiment of the present invention, a binder known inthe art to improve physical/mechanical properties or to perform aforming process may be used together with the above catalyst. Examplesof the binder may include clay, inorganic oxide, etc., and the inorganicoxide is particularly exemplified by silica, alumina, silica-alumina,silica-magnesia, silica-zirconia, silica-thoria, silica-titania, etc.The binder may be used in an amount of about 10˜90 wt %, andparticularly about 30˜70 wt % based on the amount of the catalyst, butthe present invention is not necessarily limited thereto.

Preparation of Catalyst

According to another embodiment of the present invention, a method ofpreparing a hydrogen spillover-based catalyst includes preparation ofmetal-containing zeolite, ion-exchange and thermal treatment in order.

Preparation of Metal-Containing Zeolite

In an embodiment, zeolite is prepared from a mixture comprising water, asilica source, an alumina source, and a mineralizer (OH⁻, F⁻, etc.)using, for example, a hydrothermal synthesis process. Zeolite thusprepared is zeolite having high Al content (aluminous zeolite), and istypically exemplified by P-type zeolite, A-type zeolite, X-type zeolite,etc.

Examples of the silica source may include silicate, silica gel,colloidal silica, fumed silica, tetralkyl orthosilicate, silicahydroxide, precipitated silica, clay, etc. Among the above-listedexamples of the silica source, precipitated silica and silica gel arecommercially available under the brand name of Zeosil, and colloidalsilica is commercially available under the brand name of Ludox.

In the case of the alumina source, it may be present in the form of analumina soluble salt, and examples thereof may include a sodium salt,chloride, aluminum alcoholate, hydrated alumina (e.g. gamma-alumina),pseudoboehmite and colloidal alumina.

In an exemplary embodiment, the reaction mixture for zeolite synthesismay have the following composition (represented by oxides) (molarratio):

SiO₂/Al₂O₃: about 1˜20,

H₂O/M′₂O: about 10˜120,

M′₂O/SiO₂: about 0.38˜3, and

OH⁻SiO₂: about 0.76˜6,

wherein M′ indicates the alkali metal.

Particularly in an exemplary embodiment, the reaction mixture for A-typezeolite synthesis may have the following composition (molar ratio):

SiO₂/Al₂O₃: about 1˜2.5,

H₂O/M′₂O: about 40˜120,

M′₂O/SiO₂: about 0.8˜3, and

OH⁻/SiO₂: about 1.6˜6,

wherein M′ indicates the alkali metal.

In the above embodiment, to prepare a desired type of zeolite (e.g.P-type zeolite, A-type zeolite or X-type zeolite), the specific materialcomposition and synthesis temperature (hydrothermal synthesistemperature) may be set in the above material composition range. Thebasic contents for the reaction material composition and the synthesistemperature depending on the type of zeolite are described in, forexample, W. Breck, Zeolite Molecular Sieves, Wiley, New York, p 271,1974, which is incorporated herein by reference into the presentapplication. As such, the hydrogen activation metal may be added in theform of a precursor known in the art to the reaction mixture for zeolitesynthesis. It is noted that, even when zeolite is synthesized in theabove material composition range, the silica/alumina molar ratio (SAR)of (as-synthesized) zeolite before collapse needs to be about 2 or lessin order to achieve structural collapse of zeolite as will be describedlater.

In a specific embodiment of the present invention, a crystal growthinhibitor, for example, polyethyleneglycol (PEG) may be added to thereaction mixture to control the specific surface area and the crystalsize of synthesized zeolite, and may be added at a molar ratio of forexample about up to 2, particularly about 0.1˜1.5, and more particularlyabout 0.2˜1 relative to the amount of alumina (Al₂O₃; when representedby an oxide) in the reaction mixture. Furthermore, organosilane may beused as the crystal growth inhibitor, and may be added at a molar ratioof for example about 0.0001˜0.5, particularly about 0.0005˜0.2, and moreparticularly about 0.001˜0.1 relative to the amount of silicon oxide(SiO₂; when represented by an oxide) in the reaction mixture. As such,the organosilane may be represented by Chemical Formula 1 below:R_(a)SiX_(4-a)  [Chemical Formula 1]

wherein a is an integer of 1˜3, X is a hydrolysable group uponsynthesis, for example, a hydroxyl group, a halide group or an alkoxygroup, and R is an alkyl group or an alkenyl group.

As such, the alkyl group may be in the form of being substituted with ahydroxyl group, a halide group, a thiol group, an amino group, a cyanogroup, a nitro group, an amide group, a carboxylic acid group or asulfonic acid group.

Typical examples of the organosilane may include the following and maybe used alone or in combinations, but the present invention is notlimited thereto:

[3-(trimethoxysilyepropyl]octadecyldimethylammonium chloride;[3-(trimethoxysilyl)propyl]hexadecyldimethylammonium chloride;[3-(trimethoxysilyl)propyl]dodecyldimethylammonium chloride;[3-(trimethoxysilyl)propyl]octylammonium chloride;N-[3-(trimethoxysilyl)propyl]aniline;3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxdysilane;N-[3-(trimethoxysilyl)propyl]ethylenediamine;triethoxy-3-(2-imidazolin-1-yl)propylsilane;1-[3-(trimethoxysilyl)propyl]urea;N-[3-(trimethoxysilyl)propyl]ethylenediamine;[3-(diethylamino)propyl]trimethoxysilane;(3-glycidyloxypropyl)trimethoxysilane; 3-(trimethoxysilyl)propylmethacrylate; [2-(cyclohexenyl)ethyl]triethoxysilane;dodecyltriethoxysilane; hexadecyltrimethoxysilane;(3-aminopropyl)trimethoxysilane; (3-mercaptopropyl)trimethoxysilane; and(3-chloropropyl)trimethoxysilane.

As the amount of added PEG and/or organosilane increases, the crystalsize decreases but the specific surface area increases. Illustratively,the crystal size of synthesized zeolite may be for example about 20˜3000nm, particularly about 30˜1800 nm, and more particularly about 60˜1800nm.

In an embodiment, the hydrogen activation metal is incorporated inzeolite to thus prepare metal-containing zeolite. In this regard,encapsulation of a metal cluster in zeolite may protect active sites andmay improve reaction efficiency depending on the selection of reactants,products or transition state, and various methods therefor may be takeninto consideration. In an exemplary embodiment, because the case wherethe metal cluster is stably encapsulated in the aluminosilicate matrixeven after structural collapse of zeolite is desirable, the hydrogenactivation metal may be selectively incorporated in the form of acluster having a uniform size in zeolite during preparation ofmetal-containing zeolite. However, in conventional cases, metalhydroxide may precipitate in the course of increasing pH duringsynthesis of zeolite. In an exemplary embodiment, zeolite is prepared insuch a manner that mercaptosilane is added together with a hydrogenactivation metal (M) precursor to the reaction mixture, thereby solvingthe above problems. In this case, mercaptosilane may be added at a molarratio of for example about 0.01˜0.5, particularly about 0.03˜0.2, andmore particularly about 0.05˜0.1 relative to alumina (Al₂O₃; whenrepresented by an oxide) in the reaction mixture. The mercapto group(—SH) of silane inhibits formation of metal hydroxide in an alkalimedium necessary for zeolite synthesis, and an alkoxysilane moiety ishydrolyzed and condensed with a zeolite precursor. As a result, Si—O—Sior Si—O—Al bonding is formed to thus induce crystallization of aninorganic framework around the metal-organosilane complex. Like this,the hydrogen activation metal may be selectively effectivelyencapsulated in zeolite because of bifunctionality of the organosilaneligand. Examples of mercaptosilane may includemercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, etc. Suchmercaptosilane may be removed in the course of drying and thermaltreatment which are typically performed upon zeolite synthesis. As such,thermal treatment may be carried out at for example about 573˜773 K(particularly, about 600˜700 K) for about 1˜3 hr (particularly, 1.5˜2.5hr) in an oxygen (air) and/or hydrogen atmosphere and/or inertatmosphere. These thermal treatment conditions may be illustrativelyunderstood, and the present invention is not limited thereto.

On the other hand, in an alternative embodiment, as-synthesized orcommercially available zeolite (e.g. alkali metal ion-containing zeolitesuch as Na-zeolite) is impregnated (especially wet-impregnated) orion-exchanged with a hydrogen activation metal (M) precursor, and thenthermally treated, so that the hydrogen activation metal (M) may beselectively incorporated in the form of a cluster having a uniform sizein zeolite. Furthermore, impregnated or ion-exchanged zeolite may beselectively dried before thermal treatment. As the hydrogen activationmetal precursor, any salt or complex of the corresponding metal known inthe art may be used without particular limitation so long as zeolite isimpregnated or ion-exchanged therewith. For instance, in the case wherePt is used as the hydrogen activation metal, hydrides, fluorides (e.g.PtF₆, PtF₄, [PtF₅]₄, etc.), chlorides (e.g. PtCl₃, PtCl₄, Pt₆Cl₁₂,etc.), bromides (PtBr₃, PtBr₄, etc.), iodides (e.g. PtI₂, PtI₃, PtI₄,etc.), oxides (e.g. PtO, PtO₂, PtO, etc.), sulfides (e.g. PtS, PtS₂,etc.), carbonyls (e.g. Pt(CO)₄) and/or complexes (e.g. [PtCl₂(NH₃)₂],[PtCl₂(NH₃)₂], K₂[PtCl₆], K₂[Pt(CN)₄], PtCl₄.5H₂O, K[PtCl₃(NH₃)],Na₂[PtBr₆].6H₂O, (NH₄)₂[PtBr₆], K₂[PtI₆], (NH₄)₂[PtCl₆], K₂[Pt(CN)₆],(NH₄)₂[PtCl₄], K₂[Pt(NO₂)₄], K[PtCl₃(C₂H₄)].H₂O[Pt(NH₃)₄](NO₃)₂,H₂PtCl₆, etc.) may be used, but the present invention is not limitedthereto. Also, the hydrogen activation metal precursor for wetimpregnation or ion exchange may be used in the form of an aqueoussolution and/or an organic solution. Examples of the organic solvent mayinclude, but are not necessarily limited to, acetic acid, acetone,acetonitrile, benzene, 1-butanol, 2-butanol, 2-butanone, t-butylalcohol, carbon tetrachloride, chlorobenzene, chloroform, cyclohexane,1,2-dichloroethane, diethyl ether, diethylene glycol, diglyme(diethylene glycol dimethyl ether), 1,2-dimethoxy-ethane (glyme; DME),dimethylether, dimethyl-formamide (DMF), dimethyl sulfoxide (DMSO),dioxane, ethanol, ethyl acetate, ethylene glycol, glycerin, heptanes,hexamethylphosphoramide (HMPA), hexamethylphosphoroustriamide (HMPT),hexane, methanol, methyl t-butyl ether (MTBE), methylene chloride,N-methyl-2-pyrrolidinone (NMP), nitromethane, pentane, 1-propanol,2-propanol, pyridine, tetrahydrofuran (THF), toluene, triethyl amine,o-xylene, m-xylene, p-xylene, etc.

In an exemplary embodiment, of the incorporation process, an ionexchange process using a metal hydride salt (or complex) aqueoussolution may be performed at 283˜363 K (particularly about 293˜333 K,and more particularly about 297˜313 K) for about 1˜24 hr (particularly,2˜12 hr, and more particularly 4˜6 hr), and the metal hydride saltaqueous solution may have a concentration of 0.000001˜1 M (particularly0.0001˜0.1 M, and more particularly 0.0005˜0.01 M), but is notnecessarily limited thereto.

Also, thermal treatment may be conducted at for example about 500˜800 K(particularly about 573˜773 K, and more particularly about 600˜700 K)for about 1˜3 hr (particularly, 1.5˜2.5 hr) in an oxygen (air) and/orhydrogen atmosphere and/or inert atmosphere. These thermal treatmentconditions may be illustratively understood, but are not necessarilylimited thereto.

The incorporation process of the hydrogen activation metal as above maybe more effectively applied to X-type zeolite having a comparativelylarge pore size.

In the case of synthesized zeolite having the hydrogen activation metalcluster encapsulated therein as above, optional substitution of thealkali metal ion (e.g. Na⁺) in synthesized zeolite (i.e. zeoliteextraframework) with another alkali metal (e.g. Li⁺ and K⁺), alkalineearth metal (e.g. Mg²⁺ and Ca²⁺), etc. may control structural andchemical properties of zeolite. As such, zeolite having an alkali metal(e.g. alkali metal ion-exchanged with Na^(t), other than Na⁺) or analkaline earth metal (e.g. alkaline earth metal ion-exchanged with Na⁺)may be ion-exchanged with an ammonium ion, etc. as illustrated in Scheme1 below.

As such, the amount of ion exchange may be determined in a range able toat least partially collapse the zeolite crystal structure by subsequentthermal treatment. In a specific embodiment, in the case where theamount of ion exchange is adjusted so that zeolite is partiallystructurally collapsed upon subsequent thermal treatment, more favorablereaction activity may be obtained. This is because the optimal valuebetween the gas diffusion rate of hydrogen in the aluminosilicate matrixand the surface diffusion rate of activated hydrogen may be deducedthrough partial collapse.

In this regard, in the case where the alkali metal in zeolite ision-exchanged with another alkali metal or an alkaline earth metal andthen with an ammonium ion, the degree (i.e. the molar ratio to Al) ofion exchange in zeolite may be represented by General Formula 1 below:

$\begin{matrix}{\left( {M\; 1} \right)_{n}\left( {M\; 2} \right)_{\frac{({1 - m - n})}{2}}\left( {NH}_{4} \right)_{m}} & \left\lbrack {{General}\mspace{14mu}{Formula}\mspace{14mu} 1} \right\rbrack\end{matrix}$

wherein M1 and M2 are an alkali metal and an alkaline earth metal,respectively, m may be adjusted in the range of 0.1≤m≤1, and the degreeof ion exchange of the alkali metal and alkaline earth metal may beadjusted in the range of 0≤n≤1−m.

In an exemplary embodiment, in and n in General Formula 1 may beadjusted in the range in which the NH₄ ⁺/Al molar ratio is about 0.1˜1.

Typically, an ion exchange reaction is performed by contacting zeolitewith a solution having a desired exchange ion salt. Details of thetypical ion exchange reaction are disclosed in a variety of literatureincluding U.S. Pat. Nos. 3,140,249, 3,140,251, etc., which areincorporated herein by reference into the present application. In thepresent embodiment, the cation (alkali metal or alkaline earth metalcation) of the synthesized metal-containing zeolite extraframework ision-exchanged with an ammonium ion. In a specific embodiment, theammonium ion-containing compound used for ion exchange may includeammonium nitrate, ammonium chloride, ammonium sulfate, etc. and ionexchange may be performed once or more than two times to achieve thedesired degree of ion exchange. Typically, the metal-containing zeolitemay be ion-exchanged by a contact process with an ammoniumion-containing compound aqueous solution (having a concentration ofabout 0.005˜1M) at about 20˜80° C. for about 1˜24 hr (particularly,about 5˜10 hr).

The metal-containing zeolite thus ion-exchanged is partially or fullycollapsed by subsequent thermal treatment. As such, the degree ofstructural collapse depends on the amount of ion exchange with anammonium ion. In an embodiment, the ion-exchanged metal-containingzeolite is decationized by thermal treatment at about 373˜973 K andparticularly about 473˜773 K in an oxygen atmosphere (e.g. air) and/or ahydrogen atmosphere and/or an inert atmosphere, and ultimately thecollapse of the zeolite crystal structure is induced.

The ammonium ion-exchanged zeolite (with high Al content) is present inan unstable state, and thus the crystal structure thereof may becollapsed even by only thermal treatment at a temperature less than 423K which is comparatively low. Also, aluminosilicate which is partiallyor fully structurally collapsed zeolite is decreased in specific surfacearea compared to zeolite before thermal treatment, and shows amicroporous structure. As such, the metal cluster incorporated inzeolite is dispersed in the form of being encapsulated in thecrystalline or amorphous aluminosilicate matrix after structuralcollapse.

Compared to a conventionally known common catalyst or a catalyst havinga metal cluster incorporated (encapsulated) in an unchanged zeolitestructure, the catalyst configured such that the metal particles areencapsulated in aluminosilicate which is partially or fully structurallycollapsed zeolite enables diffusion of hydrogen (at an increasedtemperature) but makes it impossible to achieve access of the organicmolecule to the metal cluster in the catalyst, and thus it may act as ahydrogen spillover-based catalyst.

According to another embodiment of the present invention, in the casewhere the catalyst configured such that the metal cluster isencapsulated in aluminosilicate which is partially or fully structurallycollapsed zeolite is applied to various hydroprocessing anddehydrogenation processes, an improved activity is manifested. Examplesof the hydroprocessing include hydrogenation, hydrodesulfurization,hydrodenitrogenation, hydrodeoxygenation, hydroisomerization, etc. Atypical example of dehydrogenation may include conversion of cyclohexaneinto benzene. Furthermore, it may be utilized in an oxygen reductionreaction to prepare hydrogen peroxide.

The catalyst according to the present embodiment may exhibit asignificantly low level for C—C hydrogenolysis. In some cases, it isnoted that it does not substantially show C—C hydrogenolysis activity.Typically, in the case of hydrogenolysis, the catalytic activity isknown to depend on the size of the metal cluster. Briefly, the smallerthe size of the metal cluster, the higher the activity. However, thecatalyst according to the present embodiment suppresses C—Chydrogenolysis activity despite the microsized metal cluster beingincorporated (dispersed) in the aluminosilicate matrix. The reason whythe activity as opposed to the prior known results is shown is that theactive sites of the surface of the catalyst reacting with the spilloverhydrogen cannot cleave C—C bonds of the organic molecule. Such reactionproperties are advantageous because loss of the hydrocarbon reactantsinto light hydrocarbon gases having low value upon hydroprocessing maybe effectively suppressed.

Moreover, even when the catalyst according to the present embodiment, inwhich the hydrogen activation metal cluster is encapsulated instructurally stable aluminosilicate, is applied to severehigh-temperature conditions, sintering of the metal may be moreeffectively suppressed, thereby exhibiting superior heat resistance,compared to a typical hydroprocessing or dehydrogenation catalystwherein the metal is exposed to the surface of a support. A betterunderstanding of the present invention may be obtained via the followingexamples which are set forth to illustrate, but are not to be construedas limiting the present invention.

EXAMPLE 1

Selective Incorporation of Pt into NaA Zeolites Having Various BETSurface Areas

Sodium aluminate (Na₂O 42.5%, Al₂O₃ 53%, Aldrich) and Ludox (AS-30, 30wt % in H₂O, Aldrich) were used as an alumina source and a silicasource, respectively. To synthesize zeolites having various BET surfaceareas, a reaction mixture (a gel composition) was added withpolyethyleneglycol (PEG, Average Mn; 1450, Aldrich) at a ratio of 0 wt%, 50 wt % and 200 wt % relative to water respectively. Then,mercaptopropyltrimethoxysilane and as a Pt precursor platinic acid(H₂PtCl₆) were added together to the reaction mixture. Consequently, thefinal composition of the reaction mixture was as follows (based on mol):

(1.5SiO₂:Al₂O₃:1.8Na₂O:38.12H₂O:0.016Pt:0.064mercaptosilane:nPEG (n is0˜0.95)).

The sufficiently mixed reaction mixture was stirred at 353 K for 18 hr,after which a solid product was obtained by filtration, and then driedat 373 K for 24 hr, affording zeolite (NaA zeolite). Thereafter, suchzeolite was thermally treated at 673 K for 2 hr in each of an airatmosphere and an H₂ atmosphere.

As for samples in which Pt was supported in synthesized NaA zeolite, theBET surface area was measured at 77 K using nitrogen adsorption.Nitrogen adsorption was measured using a BEL-Sorp-max system (BELJapan). Before measurement of the adsorption, all the samples werepretreated at 673 K in a vacuum, and the surface area of the samples wascalculated by an equation of Brunauer-Emmett-Teller (BET) under thecondition that the relative pressure (P/P₀) was in the range of0.05˜0.20. Ultimately, Pt-supported NaA zeolites having BET surfaceareas of 3 m² g⁻¹, 18 m² g⁻¹ and 38 M² g⁻¹ could be synthesized.

The amount of Pt supported in synthesized NaA-zeolite was analyzed byinductively coupled plasma atomic emission spectroscopy (ICP-AES) usingiCAP-6500 (Thermo elemental), and the mol number of Pt exposed to thesurface was analyzed by measuring H₂ and CO chemisorption amounts usingASAP2000 (Micromeretics) at 323 K (a volumetric vacuum method). H₂(99.999%) and CO (99.9%) gases were used without additionalpurification. Before analysis of the adsorption, all the samples werereduced for 1 hr while allowing H₂ to flow at 673 K (100 sccm), and thensubjected to vacuum treatment at the same temperature for 1 hr. Thechemisorption of hydrogen and carbon monoxide was measured by avolumetric method using ASAP2020 (Micromeritics), and the chemisorptionamounts thereof were measured at 323 K, 373 K, 473 K and 573 K afterreduction at 673 K for 1 hr. Specifically, the samples were pretreatedthrough the following procedures:

(i) While allowing hydrogen to flow at 100 ml/min, the sample was heatedto 373 K at 10 K/min and maintained for 30 min;

(ii) While allowing hydrogen to flow at 100 ml/min, the sample washeated to 673 K at 10 K/min and maintained for 60 min;

(iii) The sample was maintained at 673 K for 60 min in a vacuum;

(iv) The sample was cooled to adsorption temperature (323 K, 373 K, 473K, 573 K) at 50 K/min in a vacuum and maintained for 60 min; and

(v) A leak test was performed so that “outgas rate” was 10 μm/min orless at adsorption temperature (323 K, 373 K, 473 K, 573 K).

Specific measurement of the chemisorption amount was performed under thefollowing conditions:

Equilibration interval: 20 sec

Relative target tolerance: 5.0%

Absolute target tolerance: 5.000 mmHg

Measuring pressure: 2˜450 mmHg.

By extrapolation of the high pressure (50˜200 mmHg) zone of theadsorption isotherm obtained under the above conditions, the hydrogenand carbon monoxide chemisorption amounts at the correspondingadsorption temperature were determined. As such, the equilibrationinterval of 20 sec means that equilibration of the chemisorption amountis checked at an interval of 20 sec, and the relative target tolerancemeans that the case where a change in the chemisorption amount is lessthan 5% for the corresponding equilibration interval becomesequilibrium. Also, the absolute target tolerance means that the casewhere the absolute absorption amount is less than 5 mmHg becomesequilibrium. The case where both the relative and the absolute toleranceare satisfied is determined to be adsorption.

The properties of the synthesized materials are summarized in FIG. 2.Depending on the mol composition of PEG added upon synthesis of NaAzeolite, the samples were denoted as Pt/NaA-0, Pt/NaA-0.24 andPt/NaA-0.95.

Separately, mesoporous silica gel (Davisil Grade 636, Sigma-Aldrich) wasinitially wet-impregnated with a Pt(NH₃)₄(NO₃)₂ (Aldrich) aqueoussolution. The impregnated silica gel was dried at 373 K for 24 hr,calcined at 673 K for 2 hr in dry air (200 ml min⁻¹ g⁻¹), and reduced at773 K for 2 hr in a hydrogen atmosphere (200 ml min⁻¹ g⁻¹), therebypreparing a Pt/SiO₂ catalyst sample. The properties of the Pt/SiO₂catalyst sample are shown in FIG. 2.

Structural Collapse of Zeolite by NH₄ ⁺ Ion Exchange and ThermalTreatment

Each NaA zeolite synthesized by the above procedures was ion-exchangedover 6 hr at room temperature using a 0.5 M ammonium nitrate (NH₄NO₃)solution. Some of synthesized Pt-supported NaA zeolites wereion-exchanged once using 14 ml of a 0.5 M ammonium nitrate (NH₄NO₃)solution per 1 g, and the others were ion-exchanged three times using140 ml of a 0.5 M ammonium nitrate (NH₄NO₃) solution per 1 g. Theion-exchanged samples were thermally treated at 673 K in an airatmosphere, and the degree of collapse of the zeolite crystal structurewas analyzed by XRD. As such, the samples, which were ion-exchanged oncewith the ammonium nitrate solution, were denoted as Pt/NaHA-0,Pt/NaHA-0.24 and Pt/NaHA-0.95 (partial collapse), depending on the molamount of PEG added in the course of synthesis of NaA zeolite. Also, thesamples, which were ion-exchanged three times, were denoted as Pt/HA-0,Pt/HA-0.24 and Pt/HA-0.95 (full collapse), depending on the mol amountof PEG added in the course of synthesis of NaA zeolite.

XRD Analysis

The results of XRD analysis of the crystal structures before/aftercollapse of zeolite are shown in FIG. 3. As illustrated in this drawing,the synthesized Pt-containing NaA zeolites showed the typical XRDpattern for LTA, and as the collapse of the crystal structureprogressed, the peak intensity was gradually reduced (Pt/NaHA-0,Pt/NaHA-0.24 and Pt/NaHA-0.95). In the samples (Pt/HA-0, Pt/HA-0.24 andPt/HA-0.95) including fully structurally collapsed zeolite, most of thecrystal properties of zeolite disappeared. The main peak in NaA zeolitewas 2θ=7.20, and the area of the main peak after collapse of zeolite wasdecreased to less than 0.8 of the area of the main peak before collapse.Briefly, 0.8(MainP_(zeolite))>(MainP_(collapse)) is shown.

Analysis of H₂ and CO Chemisorption

In individual zeolite catalyst samples having Pt encapsulated therein,the chemisorption behavior of hydrogen (H₂) and carbon monoxide (CO)depending on changes in the temperature is shown in FIG. 4, and0.7*(H/Pt₃₇₃+H/Pt₄₇₃+H/Pt₅₇₃)/3 and (CO/Pt₃₇₃+CO/Pt₄₇₃+CO/Pt₅₇₃)/3 aresummarized in Table 3 below.

TABLE 3 Sample A B Note Before Pt/NaA-0 0.234 0.332 A < B collapsePt/NaA-0.24 0.170 0.362 Pt/NaA-0.95 0.171 0.307 After Pt/NaHA-0 0.1520.031 A > B collapse Pt/NaHA-0.24 0.095 0.033 (partial) Pt/NaHA-0.950.171 0.080 After Pt/HA-0 0.039 0.000 collapse Pt/HA-0.24 0.062 0.004(full) Pt/HA-0.95 0.075 0.007 Pt/SiO₂ 0.252 0.377 A < B A:0.7*(H/Pt₃₇₃ + H/Pt₄₇₃ + H/Pt₅₇₃)/3 B: (CO/Pt₃₇₃ + CO/Pt₄₇₃ +CO/Pt₅₇₃)/3

In the samples before structural collapse of the zeolite, both the COchemisorption amount and the hydrogen chemisorption amount weredecreased in proportion to a rise in the adsorption temperature.However, in the samples including structurally collapsed zeolite, the COchemisorption amount was totally decreased but the hydrogenchemisorption amount was increased, depending on the adsorptiontemperature rise. Specifically, in the samples (Pt/HA-0, Pt/HA-0.24 andPt/HA-0.95) including fully structurally collapsed zeolite, molecularhydrogen could not diffuse up to the surface of the metal clusterdispersed in the aluminosilicate matrix at room temperature, in view ofthe hydrogen chemisorption amount at 323 K. Also, in the samplesincluding fully structurally collapsed zeolite, the CO adsorption amounteven at a raised temperature actually approximated to zero over theentire temperature range (<0.02). This is considered to be because COhas a larger molecular size (kinematic diameter: 0.38 nm) than ahydrogen atom.

Meanwhile, the partially collapsed samples (Pt/NaHA-0, Pt/NaHA-0.24 andPt/NaHA-0.95) showed intermediate behavior between the samples beforecollapse and the fully collapsed samples, and manifested a predeterminedhydrogen chemisorption amount at 323 K. In some samples (Pt/NaHA-0 andPt/NaHA-0.95), the hydrogen adsorption amount was increased and thenstagnated or slightly decreased depending on the temperature rise.

However, the samples including partially or fully structurally collapsedzeolite satisfied the relation of0.7*(H/Pt₃₇₃+H/Pt₄₇₃+H/Pt₅₇₃)/3>(CO/Pt₃₇₃+CO/Pt₄₇₃+CO/Pt₅₇₃)/3, whereasthe samples in which zeolite was not structurally collapsed or theconventional catalyst (Pt/SiO₂) did not satisfy the above relation.

As is apparent from the results of analysis of chemisorption amounts,even when the zeolite structure is converted into a denseraluminosilicate matrix because of decationization during ion exchangeand thermal treatment, the Pt cluster is still present to beencapsulated therein.

As illustrated in FIG. 2, as results of measurement of nitrogenadsorption for the fully collapsed samples, BET surface areas were 2 m²g⁻¹, 12 m² g⁻¹ and 33 m² g⁻¹ respectively, which were slightly lowerthan the specific surface areas of zeolite samples before collapse.

TEM Image

To check whether metal (Pt) was uniformly encapsulated (supported)without size changes in the aluminosilicate matrix, TEM images forPt/NaA-0, Pt/HA-0, Pt/NaA-0.24, Pt/HA-0.24, Pt/NaA-0.95 and Pt/HA-0.95samples were analyzed. The results are shown in FIG. 5. As illustratedin this drawing, in the samples including structurally collapsedzeolite, the Pt cluster was efficiently dispersed in amorphousaluminosilicate. As such, the Pt cluster was observed to have a uniformdiameter (about 1.0 nm).

EXAMPLE 2

Analysis of Solid-State Magic Angle Spinning Nuclear Magnetic Resonance(Solid-State MAS NMR)

The sample (Pt/NaA-0) in which Pt was supported in NaA zeolite and thesamples (Pt/NaHA-0 and Pt/HA-0) in which Pt was supported in partiallyor fully structurally collapsed aluminosilicate were analyzed for ²⁷AlMAS NMR and ²⁹Si MAS NMR. The results are given in FIG. 6. Solid-stateNMR spectra were recorded on a Bruker Avance 400 spectrometer with awidebore 9.4 T magnet, operating at a Larmor frequency of 104.3 MHz(²⁷Al) and 79.5 MHz (²⁹Si). The magic angle spinning rates were set to15 kHz and 5 kHz at ²⁷Al and ²⁹Si, respectively, and chemical shiftswere recorded by a unit of ppm relative to standards of Al(NO₃)₃ and DSS(2,2-dimethyl-2-silapentane-5-sulfonic acid) for ²⁷Al and ²⁹Si,respectively.

As is apparent from the results of analysis of ²⁷Al MAS NMR, as thestructure collapsed, in the Pt/HA-0 sample, Al (60 ppm) having atetrahedral structure was decreased and simultaneously penta-coordinatedAl (25 ppm) and Al (0 ppm) having an octahedral structure were produced.On the other hand, as seen in the results of analysis of ²⁹Si MAS NMR,as the structure collapsed, Si (−89 ppm) linked to four Al atoms wasdecreased, and very non-uniform Si structure (−80 ppm˜−120 ppm) was thusproduced. The partially structurally collapsed Pt/NaHA-0 sample showed amoderate tendency.

Whereas, in the Pt/NaA-0 sample, single narrow peaks were observed inboth ²⁷Al and ²⁹Si MAS NMR spectra, which corresponded to tetrahedral Al(60 ppm) and Si (−89 ppm) linked to four Al atoms, respectively.

EXAMPLE 3

Analysis of Deactivation of Metal Surface by Sulfur

To evaluate sulfur poisoning of the Pt catalyst supported instructurally collapsed amorphous aluminosilicate, formation of Pt—Sbonding was observed by analysis of X-ray absorption fine structure(XAFS). The XAFS was analyzed in 7D-XAFS beamline at Pohang AcceleratorLaboratory, and measured at Pt L3 edge in a transmission mode. Beforethe measurement, Pt/HA-0 and Pt/SiO₂ samples in an amount of about 0.3 gwere compressed at 200 bar to thus manufacture pellets having a diameterof 13 mm, and such pellets were fitted to in-situ XAFS cells with 0.05mm thick Al window. The samples fitted to the cells were pretreated at573 K using 5% H₂S/H₂ (200 sccm) for 1 hr. The results of XAFS analysisare shown in FIG. 7 ({circle around (1)}; Pt—Pt coordination and {circlearound (2)}; Pt—S coordination).

As illustrated in this drawing, Pt/HA-0 showed radial distribution as inPt foil, whereas Pt—S bonding was formed in the Pt/SiO₂ catalyst samplehaving externally exposed Pt. In the Pt/HA-0 sample, H₂S which is thesimplest sulfur compound was inaccessible to the surface of metal (Pt).

EXAMPLE 4

Measurement of Benzene Hydrogenation Reactivity

Benzene hydrogenation was performed with the samples (Pt/NaA-0,Pt/NaA-0.24 and Pt/NaA-0.95) before structural collapse of zeolite andthe samples (Pt/NaHA-0, Pt/NaHA-0.24, Pt/NaHA-0.95, Pt/HA-0, Pt/HA-0.24and Pt/HA-0.95) having Pt supported in partially or fully structurallycollapsed aluminosilicate.

Before the hydrogenation, to minimize effects of heat and mass transfer,each sample was mixed with gamma-alumina at a ratio of 1:9 and thenmolded (75˜100 mesh), and thus used for the reaction as a finalcatalyst. The reaction was carried out using a mixture comprising 0.1 gof the catalyst and 1.9 g of SiO₂ by means of a fixed-bed continuousflow reactor, and all the samples were in-situ reduced at 673 K at an H₂flow rate of 100 sccm before the reaction. Benzene hydrogenation wasconducted under operating conditions (WHSV (h⁻¹)=525.9, 523 K,P_(H2)=472.54 kPa, and P_(benzene)=27.46 kPa).

Also, benzene hydrogenation was conducted by the same method with theconventional common catalyst (Pt/SiO₂) of Example 1.

The activity of the catalyst may be represented by a turnover rate (TOR)per total mol of Pt in the catalyst or TOR per mol of Pt exposed to thesurface as measured by hydrogen chemisorption at 323 K. The sampleshaving Pt supported in the aluminosilicate matrix formed by fullstructural collapse of zeolite have infinite TOR because the hydrogenchemisorption amount is substantially zero at 323 K. Hence, comparisonof the corresponding catalysts in which the hydrogen chemisorptionamount at room temperature is actually zero with the common catalyst isregarded as inappropriate. In the present example, the evaluation wasconducted based on TOR per total mol of Pt in the catalyst. The resultsare shown in FIG. 8.

As illustrated in this drawing, the activity was increased in proportionto an increase in the BET surface area. Among the samples having Ptsupported in aluminosilicate formed by partial collapse of zeolite, thesample having a large specific surface area exhibited much higherhydrogenation activity compared to the conventional Pt/SiO₂ catalyst.

EXAMPLE 5

Measurement of Cyclohexane Dehydrogenation Reactivity

Cyclohexane dehydrogenation was performed with the samples (Pt/NaA-0,Pt/NaA-0.24 and Pt/NaA-0.95) before structural collapse of zeolite andthe samples (Pt/NaHA-0, Pt/NaHA-0.24, Pt/NaHA-0.95, Pt/HA-0, Pt/HA-0.24and Pt/HA-0.95) having Pt supported in partially or fully structurallycollapsed aluminosilicate.

Before the dehydrogenation, to minimize effects of heat and masstransfer, each sample was mixed with gamma-alumina at a ratio of 1:9 andmolded (75˜100 mesh) and thus used for the reaction as a final catalyst.The reaction was carried out using a mixture of 0.1 g of the catalystand 1.9 g of SiO₂ by means of a fixed-bed continuous flow reactor, andall the samples were in-situ reduced at 673 K at an H₂ flow rate of 100sccm before the reaction. Cyclohexane underwent dehydrogenation underoperating conditions (WHSV (h⁻¹)=467.4, 623 K, P_(H2)=92.45 kPa, andP_(cyclohexane) =7.55 kPa).

Also, cyclohexane dehydrogenation was implemented by the same methodwith the conventional common catalyst (Pt/SiO₂) of Example 1. Theresults are shown in FIG. 9.

As illustrated in this drawing, the activity was increased in proportionto an increase in the BET surface area. Among the samples having Ptsupported in aluminosilicate formed by partial collapse of zeolite, thesample having a large specific surface area exhibited much higherdehydrogenation activity compared to the conventional Pt/SiO₂ catalyst.

EXAMPLE 6

Measurement of Thiophene Hydrodesulfurization Reactivity

Thiophene hydrodesulfurization was performed with the samples (Pt/HA-0,Pt/HA-0.24 and Pt/HA-0.95) having Pt supported in fully structurallycollapsed amorphous aluminosilicate. Before the reaction, to minimizeeffects of heat and mass transfer, each sample was mixed withgamma-alumina at a ratio of 1:9 and then molded (75˜100 mesh) and thusused for the reaction as a final catalyst. The reaction was carried outusing a mixture of 0.1 g of the catalyst and 1.9 g of SiO₂ by means of afixed-bed continuous flow reactor, and all the samples were in-situreduced at 673 K at an H₂ flow rate of 100 sccm before the reaction.Thiophene underwent hydrodesulfurization under operating conditions(WHSV (h⁻¹)=89.87, 573 K, P_(H2)=1976 kPa, P_(thiophene)=4 kPa,P_(heptane)=20 kPa).

Also, thiophene hydrodesulfurization was implemented by the same methodwith the conventional common catalyst (Pt/SiO₂) of Example 1. Theresults are shown in FIG. 10. As illustrated in this drawing, thehydrodesulfurization activity was increased in proportion to an increasein the BET surface area.

EXAMPLE 7

Measurement of Propane Hydrogenolysis Reactivity

Propane hydrogenolysis was performed with the samples (Pt/NaA-0,Pt/NaA-0.24 and Pt/NaA-0.95) before structural collapse of zeolite andthe samples (Pt/NaHA-0, Pt/NaHA-0.24, Pt/NaHA-0.95, Pt/HA-0, Pt/HA-0.24and Pt/HA-0.95) having Pt supported in partially or fully structurallycollapsed aluminosilicate.

Before the propane hydrogenolysis, to minimize effects of heat and masstransfer, each sample was mixed with gamma-alumina at a ratio of 1:9 andmolded (75˜100 mesh) and thus used for the reaction as a final catalyst.The reaction was carried out using a mixture of 2 g of the catalyst and2 g of SiO₂ by means of a fixed-bed continuous flow reactor, and all thesamples were in-situ reduced at 673 K at an H₂ flow rate of 100 sccmbefore the reaction. Propane underwent hydrogenolysis under operatingconditions (WHSV (h⁻¹)=5.41, 643 K, P_(H2)=40 kPa, P_(He)=50 kPa,P_(propane)=10 kPa).

Also, propane hydrogenolysis was implemented by the same method with theconventional common catalyst (Pt/SiO₂) of Example 1. The results areshown in FIG. 11.

As illustrated in this drawing, the samples having Pt supported instructurally collapsed amorphous aluminosilicate had low propanehydrogenolysis activity regardless of the BET surface area. Inparticular, the activity was remarkably lower compared to theconventional common Pt/SiO₂ catalyst. In the case of the Pt/SiO₂catalyst, high C—C hydrogenolysis activity is considered to result froman open pore structure thereof

EXAMPLE 8

Measurement of Propane Dehydrogenation Reactivity

Propane dehydrogenation was performed with the sample (Pt/NaHA-0.95)having partially structurally collapsed zeolite and the conventionalcommon catalyst (Pt/SiO₂) of Example 1.

Before the propane dehydrogenation, to minimize effects of heat and masstransfer, each sample was mixed with gamma-alumina at a ratio of 1:9 andmolded (75˜100 mesh) and thus used for the reaction as a final catalyst.To compare selectivity in the same propane TOR range, a mixturecomprising 4 g of the catalyst and 2 g of SiO₂ was used forPt/NaHA-0.95, and a mixture comprising 5 g of the catalyst and 2 g ofSiO₂ was used for Pt/SiO₂, and the reaction was carried out using afixed-bed continuous flow reactor. All the samples were in-situ reducedat 823 K at an H₂ flow rate of 100 sccm before the reaction. Propaneunderwent dehydrogenation under operating conditions (823 K, P_(H2)=10kPa, P_(He)=80 kPa, P_(propane)=10 kPa), and measurement was performedat WHSV (h⁻¹) of 2.7 and WHSV (h⁻¹) of 2.16 for Pt/NaHA-0.95 andPt/SiO₂, respectively. The results are shown in FIG. 12.

As illustrated in this drawing, the sample (Pt/NaHA-0.95) having Ptsupported in partially structurally collapsed amorphous aluminosilicatehad significantly improved propylene selectivity in the same TOR rangecompared to the conventional common catalyst (Pt/SiO₂). Specifically, inthe case of the sample (Pt/NaHA-0.95) having Pt supported in partiallystructurally collapsed amorphous aluminosilicate, the improved propyleneselectivity is considered to result from much lower C—C hydrogenolysisactivity thereof compared to the conventional common catalyst (Pt/SiO₂).

EXAMPLE 9

Evaluation of Metal Sintering by Thermal Treatment

The sample (Pt/HA-0.95) having Pt supported in fully structurallycollapsed amorphous aluminosilicate was thermally treated at 973 K in anH₂ (200 sccm) atmosphere for 12 hr, after which sintering of Pt wasobserved by TEM (Transmission Electron Microscope). The TEM imagesbefore/after thermal treatment are illustrated in FIG. 13.

As seen in this drawing, the Pt/HA-0.95 sample was not increased in thesize of Pt cluster even after thermal treatment of 12 hr, compared tobefore thermal treatment.

EXAMPLE 10

Selective Incorporation of Pt into Common NaX Zeolite

To dewater micropores of common NaX zeolite (13X molecular sieve,Sigma-Aldrich), thermal treatment was performed at 623 K for 6 hr in anair atmosphere, and Pt(NH₃)₄(NO₃)₂ (Aldrich) was used as the Ptprecursor.

To selectively incorporate Pt into the micropores of common NaX zeolite,ion exchange at room temperature using a 0.002 M Pt(NH₃)₄(NO₃)₂ aqueoussolution and then thermal treatment at 583 K, air atmosphere, 573 K, andH₂ atmosphere were implemented. As such, 25.9 ml of a 0.002 MPt(NH₃)₄(NO₃)₂ aqueous solution per 1 g of NaX zeolite was used suchthat final Pt content was 1 wt %. The synthesized sample was denoted asPt/NaX.

Structural Collapse of Zeolite by NH₄ ⁺ Ion Exchange and ThermalTreatment

Pt/NaX zeolite synthesized by the above procedures was ion-exchangedwith a 0.5 M ammonium nitrate (NH₄NO₃) solution at room temperature for6 hr. Such ion exchange was performed three times using 140 ml of a 0.5M ammonium nitrate (NH₄NO₃) solution per 1 g of Pt/NaX. Theion-exchanged sample was thermally treated at 573 K in an hydrogenatmosphere for 2 hr, and the degree of collapse of the zeolite crystalstructure was analyzed by XRD. The sample subjected to ion exchange andthen thermal treatment was denoted as Pt/HX.

XRD Analysis

The results of XRD analysis for the crystal structure before/aftercollapse of X-type zeolite are shown in FIG. 14. As illustrated in thisdrawing, the Pt-containing zeolite (Pt/NaX) showed the typical XRDpattern for FAU, whereas most of the crystal properties disappearedafter collapse of the zeolite crystal structure (Pt/HX). In NaX zeolite,the main peak was 2θ=10, and the area of the main peak after structuralcollapse of zeolite was decreased to less than 0.8 of the area of themain peak before collapse. Briefly, the relation of0.8(MainP_(zeolite))>(MainP_(collapse)) was manifested.

Analysis of H₂ and CO Chemisorption

As for Pt/NaX and Pt/HX samples, the chemisorption behavior of hydrogen(H₂) and carbon monoxide (CO) depending on changes in the temperature isshown in FIG. 15, and 0.7*(H/Pt₃₇₃+H/Pt₄₇₃+H/Pt₅₇₃)/3 and(CO/Pt₃₇₃+CO/Pt₄₇₃+CO/Pt₅₇₃)/3 are summarized in Table 4 below.

TABLE 4 Sample A B Note Pt/NaX 0.262 0.363 A < B Pt/HX 0.146 0.015 A > BA: 0.7*( H/Pt₃₇₃ + H/Pt₄₇₃ + H/Pt₅₇₃)/3 B: (CO/Pt₃₇₃ + CO/Pt₄₇₃ +CO/Pt₅₇₃)/3

As is apparent from the above table, X-type zeolite exhibited therelation of A>B after structural collapse of zeolite, as in A-typezeolite.

Analysis of Solid-State MAS NMR

The sample (Pt/NaX) having Pt supported in NaX zeolite and the sample(Pt/HX) having Pt supported in structurally collapsed aluminosilicatewere analyzed for ²⁷Al MAS NMR and ²⁹Si MAS NMR. The results are shownin FIG. 16. Solid-state NMR spectra were recorded on a Bruker Avance 400spectrometer with a widebore 9.4 T magnet, operating at a Larmorfrequency of 104.3 MHz (²⁷Al) and 79.5 MHz (²⁹Si). The magic anglespinning rates were set to 15 kHz and 5 kHz at ²⁷Al and ²⁹Si, andchemical shifts were recorded by a unit of ppm relative to standards ofAl(NO₃)₃ and DSS (2,2-dimethyl-2-silapentane-5-sulfonic acid) for ²⁷Aland ²⁹Si, respectively.

As is apparent from the results of analysis of ²⁷Al MAS NMR, as thestructure collapsed, in the Pt/HX sample, Al (60 ppm) having atetrahedral structure was decreased and simultaneously penta-coordinatedAl (25 ppm) and Al (0 ppm) having an octahedral structure were produced.On the other hand, as seen in the results of analysis of ²⁹Si MAS NMR,as the structure collapsed, Si (−89 ppm) linked to four Al atoms wasdecreased, and very non-uniform Si (−80 ppm˜−120 ppm) was thus produced.

Whereas, the Pt/NaX sample showed single narrow peaks in both ²⁷Al and²⁹Si MAS NMR spectra, which corresponded to tetrahedral Al (60 ppm) andSi (−89 ppm) linked to four Al atoms, respectively.

EXAMPLE 11

Measurement of Benzene Hydrogenation Reactivity of Pt/NaX and Pt/HX

Benzene hydrogenation was performed with the sample (Pt/NaX) having Ptsupported in NaX zeolite and the sample (Pt/HX) having Pt supported instructurally collapsed aluminosilicate.

Before the hydrogenation, to minimize effects of heat and mass transfer,each sample was mixed with gamma-alumina at a ratio of 1:9 and thenmolded (75˜100 mesh), and thus used for the reaction as a finalcatalyst. The reaction was carried out using a mixture comprising 0.2 gof the catalyst and 4 g of SiO₂ by means of a fixed-bed continuous flowreactor. All the samples were in-situ reduced at 573 K at an H₂ flowrate of 100 sccm before the reaction. Benzene underwent hydrogenationunder operating conditions (WHSV (h⁻¹)=263.0, 523 K, P_(H2)=472.54 kPa,P_(benzene)=27.46 kPa). The results are shown in FIG. 17.

As illustrated in this drawing, the structurally collapsed Pt/HXcatalyst exhibited higher hydrogenation reactivity compared to thePt/NaX catalyst in which all reactants were accessible to the surface ofmetal.

EXAMPLE 12

Measurement of Propane Hydrogenolysis Reactivity of Pt/NaX and Pt/HX

Propane hydrogenolysis was performed with the sample (Pt/NaX) having Ptsupported in NaX zeolite and the sample (Pt/HX) having Pt supported instructurally collapsed aluminosilicate.

Before the hydrogenolysis, to minimize effects of heat and masstransfer, each sample was mixed with gamma-alumina at a ratio of 1:9 andthen molded (75˜100 mesh), and thus used for the reaction as a finalcatalyst. The reaction was carried out using a mixture comprising 1.5 gof the catalyst and 4 g of SiO₂ by means of a fixed-bed continuous flowreactor, and all the samples were in-situ reduced at 723 K at an H₂ flowrate of 100 sccm before the reaction. Propane underwent hydrogenolysisunder operating conditions (WHSV (h⁻¹)=3.60, 723 K, P_(H2)=90 kPa,P_(propane)=10 kPa). The results are shown in FIG. 18.

As illustrated in this drawing, the structurally collapsed Pt/HXcatalyst exhibited much lower hydrogenolysis reactivity compared to thePt/NaX catalyst in which all reactants were accessible to the surface ofmetal. In the case of the Pt/NaX catalyst, high C—C hydrogenolysisactivity is considered to result from an open pore structure thereof

EXAMPLE 13

Measurement of Propane Dehydrogenation Reactivity of Pt/NaX and Pt/HX

Propane dehydrogenation was performed with the sample (Pt/NaX) having Ptsupported in NaX zeolite and the sample (Pt/HX) having Pt supported instructurally collapsed aluminosilicate.

Before the dehydrogenation, to minimize effects of heat and masstransfer, each sample was mixed with gamma-alumina at a ratio of 1:9 andthen molded (75˜100 mesh), and thus used for the reaction as a finalcatalyst. The reaction was carried out using a mixture comprising 2 g ofthe catalyst and 4 g of SiO₂ by means of a fixed-bed continuous flowreactor, and all the samples were in-situ reduced at 853 K at an H₂ flowrate of 100 sccm before the reaction. Propane underwent dehydrogenationunder operating conditions (WHSV (h⁻¹)=7.21, 853 K, P_(H2)=10 kPa,P_(He)=70 kPa, P_(propane)=20 kPa). The results are shown in FIG. 19.

As illustrated in this drawing, the structurally collapsed Pt/FIXcatalyst exhibited much higher propylene selectivity compared to thePt/NaX catalyst in which all reactants were accessible to the surface ofmetal. However, the Pt/NaX catalyst having an open pore structuremanifested high C—C hydrogenolysis activity and thus low propyleneselectivity.

Accordingly, modifications or variations of the present invention may beeasily utilized by those having ordinary knowledge in the art, andshould also be understood as falling within the scope of the presentinvention.

The invention claimed is:
 1. A hydrogen spillover-based catalyst,comprising: crystalline or amorphous aluminosilicate formed by partialor full structural collapse of zeolite having a silica/alumina molarratio of 2 or less, wherein the zeolite is P-type zeolite, A-typezeolite or X-type zeolite; and a hydrogen activation metal (M) clusterencapsulated in the aluminosilicate, wherein the hydrogen activationmetal (M) cluster is incorporated into the zeolite using impregnation orion-exchange, the metal cluster-incorporating zeolite is ion-exchangedwith an ammonium ion (NH₄ ⁺), and the ion-exchanged zeolite is thermallytreated, wherein changes in hydrogen and carbon monoxide chemisorptionamounts depending on a temperature satisfy the following relation:0.7*(H/M ₃₇₃ +H/M ₄₇₃ +H/M ₅₇₃)/3>(CO/M ₃₇₃ +CO/M ₄₇₃ +CO/M ₅₇₃)/3wherein H/M is a chemisorption amount (mol) of a hydrogen atom per totalmol of M, CO/M is a chemisorption amount (mol) of carbon monoxide pertotal mol of M, and subscripts represent adsorption temperatures (K). 2.The hydrogen spillover-based catalyst of claim 1, wherein thesilica/alumina molar ratio of zeolite is 1˜2.
 3. The hydrogenspillover-based catalyst of claim 1, wherein upon partial or fullstructural collapse of zeolite, an XRD (X-ray Diffraction) pattern ofthe catalyst shows the following:0.8(MainP _(zeotite)) >(MainP _(collapse)) wherein MainP_(zeolite)is aarea of the highest peak among XRD peaks of zeolite before collapse, andMainP_(collapse)is a base area of an XRD peak at the same 2θof zeoliteafter collapse.
 4. The hydrogen spillover-based catalyst of claim 1,wherein the hydrogen activation metal is any one or more selected fromthe group consisting of Groups IB, VIIB and VIII metals on a periodictable.
 5. The hydrogen spillover-based catalyst of claim 1, wherein themetal cluster has a diameter of 0.5 ˜50 nm.
 6. The hydrogenspillover-based catalyst of claim 1, wherein an alkali metal/Al molarratio in the aluminosilicate is 0.9 or less.
 7. The hydrogenspillover-based catalyst of claim 1, wherein an alkaline earth metal/Almolar ratio in the aluminosilicate is 0.45or less.
 8. The hydrogenspillover-based catalyst of claim 1, wherein the amorphousaluminosilicate has micropores with a diameter of less than 0.29nm atroom temperature.